Frangible missile structure



1945- c. EfcHoATE ETAL FRANGIBLE MISSILE STRUCTURE Filed March 14, 1941 2 Sheets-Sheet 1 W Z} a vr nw am an t r e M7, M

June 5, 1945. Q cHQATE ETALv 2,377,675

FRANGIBLE MISSILE STRUCTURE Filed March 14, 1941 2 Sheets-Sheet 2' I ave 71 2'02": Caz-ZiZe E. Lhoaie, Buzzer Z E. Ybzvns and, J2'

3 lw zwfT M, ymw g g Patented June 5, 1945 UNITED STATES PATENT F Pica.

FRANGIBLE MISSILE STRUCTURE Carlile E. Choate, Monson, Maine, and Robert E. Townsend, Jr., Boston, Mass, assignors to Devonshire Research Corporation, Boston, Mass, a corporation of 7 Massachusetts Application March 14, 1941, SerialNo. 383,244 2 Claims. ,(Cl. 102-64) and treating, target practice and other fieldsof activity where confined matter is to be released or distributed on impact or otherwise.

More particularly the invention aims to pro-' vide frangible chambered bodies for such articles and devices which may be produced inexpensively, rapidly and in large quantities by a molding or like forming process availing of the numerous moldable, plastic, or like tenacious materials and compositions subject to a soft-working, forming or shaping condition and which are reducible to a set, rigid or solid state, as in the practice of production methods involving molding and like integral, unitary or so-called final form structural formation processes.

1 In the drawings,

Fig. 1 shows in elevation one form of container or carrier of the class and suitable for the purposes stated, and representing one typical embodiment of our invention;

Fig. 2 is a section on the line 2-2 of Fig. l; and

Fig. 3 is another diametral section of the device of Fig. 1 but with the inner or divider element in elevation.

= Referring to the drawings in more detail, and first to Figs. 1 to 3, the container or carrier device, viewed externally and in its entirety in Fig. 1, comprises an outer closed or continuous-walled shell-like member or body 5, in this instance of true or approximate spherical form. Within this outershell or body member 5 there is disposed in fixed position an inner hollow member, body or container 6, here represented for the purposes of illustration as having the general form of a triangular pyramid, shown by dotted lines in Fig. 1 and seen in partial section in Fig. 2 and in elevation in Fig. 3. The four flat or substantially flat faces of this pyramidalinner container 6 are indicated at 1, 8, 9, and I0, respectively.

-The walls 1 to ID of the inner element 6 define within them a separate closed chamber or com-v partment H, of less volume than that defined by the wall of the outer shell or container 5 as a whole. The apices of the inner element 6 are adapted to engage and be supported on and by the enclosing wall of said outer element or body 5." Thus there is provided within said outer element a predetermined space unoccupied by the inner container 6, constituting an outer receiving or carrier space or compartment 12. Such separate and herein'outer compartment i2 is in this instance spherically continuous about the inner element, as an externally spherical stratum-likechamber. a

As an important feature of our invention, the walls of at least one and generally of both the inner and the outer compartment-defining -elements 5 and 6 are composed of a frangible mate rial or composition. Further, at least the outer element, and preferably both of them, are produced by a molding or like forming operation. In so constructing the walls, any of the known or preferred plastic or other moldable com'posi- I tions: and materials may be employed which are adapted to set or be reduced to rigid or solid form following such molding or similar integral formation process and which satisfy the other requirements herein indicated. Such materials may be selected from the various carbon compounds, synthetic resins and other substances, compounds and compositions adapted for shaping when soft and subsequently hardening to a set, rigid state, including the various commercially available resins, gums, and condensation and reaction products, such for example as numerous of the phenolic-aldehyde, urea-formaldehyde and other aldehyde and analogous compositions. The term plastic or plasticity as used herein is intended to embrace any such materials, com-' pounds and compositions, being employed inthe broad sense of moldability or adaptation for shaping as by molding, accordingly including by way of further example glass and other vitreous materials. In any case, however, the material is selected with a view to its affording in the complete or set stage the desired characteristics of substantial rigidity, tenacity and pressureresi'sting strength but nevertheless having the property of rupturing or fragmenting by impact or blow of predetermined minimum force, which property is herein indicated by the term frangible. A further important selection of the particular the containers or casings of of reduction in weight, together with those of ready availability in adequate large quantities and at relatively low cost, as compared for example with-brass, steel and dther metallic materials heretofore employed in ordnance devices. It is also particularly noted that the materials menmaterial for molding tioned may be reinforced as by-the admixture consideration in the our invention is that tions of wood or other substance, or by metallic reinforcing sheets, strips and other elements, either as to the inner or the outer wall members, particularly in those instances where it is desired to employ a content under substantial pressure.

In constructing the container means, its inner and outer elements may be separately molded or otherwise formed,.theout'er element preferably being molded in two substantially hemispherical sections, as represented diagrammatically by the dotted diametral line in Fig. 2. These sections, after insertion of the inner element,-are secured and preferably sealed together either by softening and uniting the plastic material itself or through the medium of threaded, overlapping or other joint formations, with appropriate hermetic and generally pressure-tight sealing provisions whenever the particular content and circumstances of use so prescribe.

The inner container element, if separately" formed such as the member 6 of Figs, 1 to 3,

may be similarly molded in one or more parts joined: and sealed. As

integrally or otherwise previously indicated,;at least the inner element may in. some instances be, cpnstructed otherwise than of plastic material, as for example of a suitable sheet metal, appropriately lined if desired for prevention of corrosive or other chemical action upon. it by its content, it being againnoted that the, materials as herein intended by broad terms plastic. ormoldable include cellulosiccompositionssuch as molded pulp and also glass and various natural substances or, admixtures.

thereof, such as those of the ceramic. and other types.

. In accordance with-our invention provision is made. for separatefilling. of the individual compartments in the main or outer container 5,.

whether such compartments be disposed one within another or otherwise. In the example ofv Figs. 1 to 3, the outer and. herein spherically continuous compartment l2, defined between the walls of the inner member 6 and the spherical;

wall of the outer shell 5 is accessible through a filling. aperture means. here represented as, a threaded cap l4 receivable in. the like threaded aperture" wall. Such cap, which may countersunk into the outer face of the latter and maybe circumferentially flanged as seen in Fig. 2, to limit its insertion. A slot or other non- As best seen in Fig. 2, access to the inner ele-. ment-G also is afforded, after completion ofthedevice as a whole, through the medium of an integral or other filler tube or bushing I6. This latter maybe a unitary orotherv part of either the inneror the outer container,. and of like material as one of them. Theinner end of such filler tube l6 communicateswith the inner. chamber ll of. the pyramidal inner member 8. of. Figs. 1.to 3,- through an opening I! disposed,. for reasons of. manufacturing convenience. in, one or another of its fiat faces-,rhereinthe wall ID. This. fill tube l6 opens outwardly through an appropriate aperture I8 in the wall ofthe-outer container 5, its. outer end having. a closure or cap IBwhich may be and is herein-shown aslsubstan I-3- having. suitable closure:

be. of the same material as. that of the container element 5,. desirably tially similar to the cap l5 previously described.

By comparison of the several Figs. 1, 2 and 3, it will be noted that the two filling apertures l3, l8 and their respective closures l5, I9 are so arranged, herein non-oppositely, that each is partly diagrammatically by the stippled areas about the points of the inner container 6; Figs. 2 and 3.

It is an important feature of the invention that the frangible missile or container means as disclosed is adapted to be completed save for filling. and to be shipped. or stored empty but'in immediate readiness for filling and use. Where immediate filling is not objectionable the bomb or like missile-container device asa whole may be filled attendant on its construction, or at any convenient later time, as to any or all. of its. separate compartments. But frequently the ca pacity for filling: in situ, as for example at. or near a landing field. and shortly prior to take-off of the. distributing plane, is an important advantage, particularly in connection with content materials of explosive, gaseous, incendiary or other dangerous types.

In the use of the device of our invention itlis contemplated that the separate compartments such as the receiving spaces II and [2 of Figs. 1V to- 3 will each. have a differentcontent, adapted. to react chemically when permitted to unite upon fracture of the compartment walls, or selected to have, when-so released a cooperative or cumulative effect appropriate to the particular result desired. Such different contents may be. two or more gases, liquids or solids, or combination thereof, or a gas and an-explosive, an explosive andan incendiary material, or any other desired be fractured or at least opened by cracking. sub

stantiallysimultaneously with the outer one,.maycontain a destructive, poisonous or other injurious gas suchas dichlorodiethylsulfide (mustard gas), carbonyl chloride (phosgene), a picric derivative or othertype which is then free to attack.

the exposed and vulnerable individual objectives- When a' primarily incendiary effect is desired.

the contents of the separate chambers may be of a chemicalnature such as to produce violent combustion upon union attendant on the'fractureof the compartment walls. As anexample: for such incendiary purpose,- one of the compartments, preferably the inner one,. may be filled with a mixture comprising mainly comminuted zinc; another or outer compartment containing.

perchloricacid (HC104) Another highly effective embodiment of the invention comprises: the formation of the outer' container itself, such as the shell=5 of Figs. 1 to 3,,

of magnesium, desirably roughened or irregularly formed at the inner face of the shell wall for better frictional engagement with the immediate content, an immediately adjacent chamber being filled with a, thermite or like composition such as a mixture of aluminium powder, iron particles, and sodium or potassium perchlorate. In-such instances the inner or other compartment, such as I I of Figs. 1 to 3, may carry an explosive, where a spreading effect is desired, or a substance adaptedto cooperate with the material of the outer chamber to initiate or assist in starting or augmenting the incendiary effect.

Where the object is primarily that of gas distribution, the contents of the separate compartments need not necessarily be of ,a character to interact with each other with incendiary or explosive effect but may consist of gases having different specific gravities or other differing properties adapting each for attacking different objectives or for other more or less specialized results.

In the event that the armed forces of this country should by way of retaliation elect to employ attack means not now sanctioned by the rules of humane warfare as presently recognized by it, the means of the present invention in certain of its forms might be more readily adapted to such purpose than are existing ordnance devices of like nature.

From the foregoing it will be evident that our present invention is in no sense limited as to any particular content for any'or all of the plurality of compartments but is primarily concerned with the container structure and its manufacture, thus having as a main object the provision of universal adaptable chambered holder, container or carrier devices for missile and like purposes. While in certain of its aspects the .invention may be otherwise embodied than by a device having an external globular or non-angular conformation, such as the substantially true spherical form illustrated, the approximate spherical form is generally preferred and specially cooperates toward the desired results. Such generally spherical outer shell or wall form for the devices has numerous advantages peculiar to the intended uses. Among these are its substantially total symmetry, insuring fracture or fragmentation irrespective of the point of impact. Further, the outer spherical Wall offers a uniform resistance to the pressure of the air or other medium through which the device is passing, wholly regardless of the particular portion which may be leading in the direction of travel at any given time. This fact is of significant importance in connection with the distribution of the devices from an altitude, since the effect of cross or other winds is reduced to a minimum, by reason of its presentation of a uniformly curved surface in any and all directions. Thus the missiles of the invention are adapted for release from greater altitudes, since the target can be determined with greater certainty and less need for complicated corrections for various weather conditions and despite the fact that in their travel from high altitudes the devices may pass through winds of widely variant directions'at different air levels.

Another important consideration in this connection is the substantially uniform reaction of the materials of the spherical device throughout their entirety .to temperature changes, noting that in descent from high altitudes the device may pass abruptly from an air stratum at a given temperature to one of a widely variant higher or lower temperature.

While the spherical or other device of the invention may be variously dimensioned, it is considered that an outer container havingthe approximate size of a polo ball, about 4 in. in diameter or thereabouts, is convenient and appropriate to the main generality of contemplated uses. 7 Spherical containers of that approximate closure. Large quantities of the devices may be carried in a given air vehicle, from which they may be distributed over wide areas, either by simply droppingor to a markedly greater extent by projection mechanically, or under the influence of compressed air or the like, being thus in effect sprayed forth, with greatly increased distributional possibilities and at a rate or distributional density which may be governed to suit the particular circumstances. Further, any desired quantity of such devices may be placed in a suitable basket, casing or other holding means, for simultaneous release or projection, with the assumption that practically all of them will be fractured or fragmented to perform their intended purpose.

Numerous other uses and advantages for the plastic, moldable or other frangible and chambered devices of our invention will be apparent to those skilled in the various fields of use to which they are adaptable.

Particularly in the instances of either an explosive or an incendiary content for any one or more of the plural chambers, the latter may be equipped with one or more detonating or combustion initiating fuses, as the case may be, of any number or preferred form, including impact, time or other type of such devices. Also, to promote frangibility, particularly in the stronger walled types, the container walls maybe formed with lines or zones of weakness, such as corrugations and depressions, relatively thin portions or like variant formations, regularly or otherwise disposed, upon any or all of the walls. With respect to the outer container wall, however, any such irregularities preferably are disposed at the inner face of the wall, so as not to increase or make irregular the external air resistance of the device.

Further, the various features of the invention here illustrated may be otherwise arranged or combined than as shown in the drawings by way of example; any required plurality of frangiblewalled compartments or chambers may be supplied, either by the provision of additional inner containers or additional divider walls, by subdividing one or more of the compartments, by providing a further and smaller-spaced container within the inner casing, flask or the like such as the element 6 of the present figures or in other manner conforming to the spirit of the invention. The ready susceptibility of the latter to the requirements for rapid and inexpensive large scale production will be abundantly evident from the foregoing description.

7 L011! inventionii :not ;limited ito Ethe zparticular embodiment thereof illustrated :and described herein, andweisetiorthzitsscopeiin our following claims:

l1. impact operative charge-12am 'ng :bom-b -or.:she11 :of spherical external rform comprisin nwfrangihle router z-anfl inner walls molded their entirety of a ifrangible asynthetic resinous plastic ;material, fsaid walls interconnected in :fixedrelation 'to define 'a zplurality .of separate :closed .:ani;l :norma-lly znon-icommunicating compartments, :each having externally :accessible :filler :and re- :movable closure tmeans smoothly conforman'tito said external spherical :form, and said :inner .walls "defining n pyramida'l inner compartment having :its 'apices directly lbonded to the surrounding spherical outeriwa'll. 1 r

2. A compartmental aimpact 400mb having 'all 'its -contaim'ng walls molded o'f rilastic material, sai'cl bom'b compr ising, in combination, a closed hollow inner shell member =mo'lcled "of frangible synthetic resinous plastic material anti-providing :an inner closed compartment within it, a larger spherical outer shell member of like -Tfrangib1e :zgazwems synthetic resinous matureenclosing the inner imembersso :as to provide :azsubstantially continuous tcompartmerrt between the two membershsaid- 'outerzshell:membencomprising aplurality of meatling ihemisphericalsections, said sections withgthe xinner'shellrmemberidirectlyxpositioned vbyiancl en- .clnsed within :them being integrally :sealecl 110- gether rby *aplastic union of thermaterialnf their adjoining portions, the inner :shell member havgeneral.formaofatriangular'pyramidhav- :ing its capicesin direct en agementwithend sup- :ported :by the wall :01 the spherical outer shell .member, :means iimmovably interconnecting the inner ;and: outer shell members, a plurality of fill 'aperturesdn 'theaouter shell'member, a.single:fi1l aaperturezimthe inner shell member, tubular means affording :closed :communication'between the fill ;aperture:of the innerrs'hellimemberand one .fill aperture of the "outer .Shll member, and removable sealing closure means for the "fill apertures fO'f the outer shell member smoothly conforming to its outer spherical surface.

CARLILE 'E. 'CHOATE. ROBERT E. TOWNSEND, J a. 

